Speaker static/hiss?

Interesting post for me. I just added two Parasound A21+ amplifiers to my system and am having the same hiss at close proximity to the speakers (2-3 inches) with no source material playing. When I installed the amps I didn't have any sound coming through from my sources and no hiss either. Spent two or three hours trying to figure out what I did wrong, As a last resort I turned the pre's volume all the way up and got a faint signal, so I turned the gain up on the amplifiers channels to give me reasonable volume. I've never had amps with adjustable gain before and it would never occur to me that turning it up too much might have started the hiss.

I have some headroom for the levels that I listen at, so I will try turning the gain down a little and see what happens.

BTW - I had been using Holmz #2 suggestion. It works.

Thanks - Jim S.

+1 @panzrwagn 

+1 @mulveling 

Suboptimal gain structure FTW. Somebody has some pro audio experience and a good mentor. I had both and the two key lessons I learned about signal chain were grounding (hum) and gain structure (noise and headroom). And both are seriously ignored in most hifi systems. If either are problematic in your system, the fix is to properly set your system up, not shop for new pieces that happen to match your system needs.

Do you have a tube ,amp, or preamp ? That’s most likely the culprit.

When no source but equipment is turned on is there still a hiss? I use a pc for my source with an asus essence stx ii 7.1 sound card with crown xls 1502 and 2502 along with an xti 6002 and two cerwin vega subs one being a cvx-21s and an el36dp, my speakers and only the cvx-21s when turned all the way up no hiss or sound if my pc is turned off. I'm not sure about the el36db i've never tested that yet but when i turn the gain all the way up it rumbles a little. Now when my pc is turned on even with the gain low the tweeters make a hiss noise up close while the cvx-21s no audiable noise except what it's suppose to be playing. So if there is no hiss when source is turned off it's the source itself that is causing the hiss, if it's a grounding problem it hums not hisses, it's normal for tweeters to hiss since they play so high but don't worry when being used that hiss is unheard at a decent volume level.

Nothing to worry about. I had a amp that did the same thing.

Your speakers have slightly higher than average sensitivity. A21+ is a good amp that looks like a reasonable pairing here. That Marantz though - a 13.2 channel preamp? Holy cow! That thing is so chock full of multi-channel features they don’t even bother to list a gain spec. But that would be the most suspect component here. Maybe it has a variable or selectable gain feature you could play with? But really, the easiest solution should be to lower the gain pots on your A21+ until you reach a good balance. You're lucky to have an amp with that feature - most modern hifi amps don't (some of us get antsy about extra potentiometers in the signal path - same with balance controls). What do you currently have those adjusted to? Are they at max gain?

What is your gear ??
 

Parasound A21+ amp

Paradigm Founders 100F

Marantz 8805 pre amp

Bluesound Node (2021 model)

Furman SPR-20 

Dedicated 20amp service to the room with Audioquest 20amp receptacles. 

SVS SB3000 subs (four-one in each corner of the room)

some other odds and ends. 

What is your gear ??

It’s caused by suboptimal gain structure. You have way too much active gain after the volume control (this means your combined preamp and amplifier circuitry - which generates higher noise floor per extra dB of gain even if signal-to-noise remains the same), relative to your needs determined by listening level and speaker sensitivity.

I have this situation myself, with very sensitive 96dB / 2.83V Tannoys. I easily notice the signal-to-noise ratio differences between preamps. I need to keep the preamp gain below 14dB, and even at that level the preamp’s signal-to-noise ratio has to be VERY high to avoid an audible "hisssssss" at volume = 0. The ARC Reference 6 has a stellar signal-to-noise. VAC Master also excellent. Some other preamps...are not so great.

Often inserting signal attenuators (e.g. Harrison Labs) to the tube of ~ 10dB is recommended to push the noise floor down while utilizing more gain from your circuitry. However, if you have the Parasound amps, as @russ69 mentioned - turning down the gain pots should be the best solution here.

It’s normal no effort needed.

… try the ground lift switch. Give it 5 mins to let it settle.

Hiss is not solved with a ground.

You need to

1. Use a lower noise amp, or
2. Avoid being on all fours with the ear up to the speaker.

I would choose #2.

It's just circuit noise. Try the gain controls and whole you're at it, try the ground lift switch. Give it 5 mins to let it settle.

I thought about the gain knob. I’ll give it a shot. 
 

any recommendations for the setting to get it right?

A Discussion About Idle Hiss – Upscale Audio

Turn the gain down on your A21. The knobs are on the back.

Likely your amp.